Our proposal concerns itself with the qualitative and quantitative analysis of human cerebrospinal fluid (CSF) for a selected list of compounds (i.e. tryptamine and its congeners) which are thought by many investigators to play an important role in the pathophysiology of schizophrenia. These compounds will be detected as their pentafluorobenzoyl derivatives using gas-liquid chromatography. With an electron-capture detector this technique is sufficiently sensitive to detect as little as 10 picograms of material. The study has been prompted by the recent discovery that tryptamine exists in human brain. Acute and chronic schizophrenics will be used and the control group will consist of neurological patients undergoing investigation by lumbar puncture.